1. Field of the Invention
The invention pertains to belt driven barrel fans movably positionable upon a floor surface.
2. Description of the Related Art
Large industrial type fans for circulating air adjacent a floor surface are often used in factories and warehouses for cooling and ventilation purposes. Such fans may be located adjacent an open door for moving air into an enclosure, or for blowing fumes away from a work area. A common fan of this type is known as a xe2x80x9cbarrel fanxe2x80x9d so named as the propeller or blade housing is in the form of a tubular barrel open at each end. A rotatable blade shaft is coaxially located within the housing having a blade mounted thereon. In conventional constructions, an electric motor is located within the housing and drives the blade shaft through a flexible belt. Guard grills are normally located at each end of the barrel.
The air circulated by the fan passes through the interior of the barrel housing, and over a period of time, a large amount of unfiltered air passing through the housing causes dust and dirt particles to build up on the blades, grills and electric motor. While such buildup of airborne debris on the blades and grills can be cleaned therefrom, the deposit of such foreign matter within the motor is difficult to remove and will enter the motor interior, reduce the flow of required cooling air through the motor, and often cause shorting or premature motor overheating and motor failure.
Also, the maintaining of the belt tension between motor and blade shaft of conventional barrel fans requires periodic adjustment. As the maintenance of fans is usually overlooked, it is a common problem to run fans until they malfunction and must be replaced, or major components must be replaced, and the invention pertains to a low maintenance industrial type fan of high capacity which eliminates some of the problems previously present with this type of fan.
It is an object of the invention to provide a barrel fan driven by an electric motor wherein the electric motor is located exteriorly of the barrel fan housing, and is not within the air flow path.
A further object of the invention is to provide a barrel fan driven by an electric motor wherein the electric motor is located exteriorly of the barrel fan housing, is pivotally mounted, and a spring interposed between the barrel fan housing and electric motor maintains tension within the motor drive belt.
An additional object of the invention is to provide a barrel fan operated by an electric motor located exteriorly of the barrel fan housing wherein the electric motor is enclosed within a skirt for protective and aesthetic purposes and ventilation means are provided to circulate cooling air over the electric motor.
A barrel fan in accord with the invention includes a relatively large tubular housing which may be 42 inches in diameter, or greater, wherein each end of the housing is provided with a protective grill, and interiorly, a blade or propeller shaft is rotatably mounted upon bearings and supports the blade assembly. The shaft also includes a belt sheave of the V-belt type. Housing support structure is formed on the barrel fan housing for supporting the housing on the floor such that the blade shaft will be substantially horizontally disposed, and the support structure usually includes wheels for facilitating portability of the fan.
Conventional barrel fans mount an electric motor within the barrel fan housing which is connected to the shaft sheave by a V-belt or may be directly attached to the shaft. However, in the instant invention, an electric motor is mounted exteriorly of the fan housing and the motor drive belt passes through the housing.
In accord with the invention,.the electric motor is pivotally mounted upon the axle supporting the fan housing wheels, this axle is mounted upon the fan housing by a bracket and disposed parallel to the blade shaft. The pivotal mounting of the motor support upon the axle is achieved by conventional U-bolts, and a Y-shaped spring is interposed between the fan housing and electric motor casing tending to pivot the electric motor about the wheel axis in a direction away from the blade shaft. This biasing force maintains the desired tension on the V-belt, and should V-belt replacement be necessary, the electric motor can be easily pivoted toward the blade shaft to release the tension on the belt and permit a new belt to be easily placed upon the blade shaft and electric motor sheaves.
Preferably, a metal skirt removably attached to the barrel fan housing extends around the electric motor, and partially encloses the fan housing wheels. This skirt hides the electric motor from sight and further protects the electric motor from damage and encloses the belt at the motor sheave for safety purposes. Ventilation openings are defined in the lower portion of the fan housing to permit air within the fan housing to enter the shield and circulate air therein for cooling the electric motor. As the bottom of the shield is open, ventilating air entering the shield is discharged to the atmosphere.
The above described relationship has several advantages. By locating the electric motor exteriorly of the barrel fan housing, the air circulated by the fan is not passing over the electric motor, as is the case with electric motors mounted interiorly of the fan housing so that maximum air flow through the housing is achieved, and the accumulation of dust and foreign particles on the electric motor in accord with the invention occurs much slower than with conventional barrel fans. Further, the use of an economical spring interposed between the barrel fan housing and the electric motor casing permits the proper belt tension to be maintained on the V-belt even though some stretching may occur and maintenance in this respect is eliminated and replacement of the belt is easily performed. The mounting of the electric motor on the wheel axle reduces costs and eliminates a special supporting bracket for the motor, and the skirt defining a combination motor and wheel enclosure results in an attractive barrel fan appearance while providing protection for the belt and motor.